TAIPEI, Taiwan (CNN) -- Rescue crews combed through mountains of twisted concrete and steel Tuesday with hopes of finding survivors from an early-morning earthquake that claimed the lives of at least 1,455 people in Taiwan, state-run television said.

State radio described it as the strongest tremor to hit the island in more than a decade. The Interior Ministry's disaster  management center reported that 1,198 people were killed and some 3,700 injured. About 1,245 people were feared trapped and more than 1,000 homes were destroyed.

The quake struck at 1:47 a.m. (1747 GMT Monday). The U.S. Geological Survey, which monitors seismic activity worldwide, said the tremor had a preliminary magnitude of 7.6 and was centered in Nantou county, some 90 miles (150 km) southwest of the capital Taipei. Taiwanese officials put the magnitude at 7.3.

Most of the victims were found in the central city of Taichang and nearby Nantou, where hospitals quickly filled with injured people. Morgues were also near capacity.

Nantou County Executive Peng Pai-hsien said that 470 county residents had been killed and 100,000 left homeless. He appealed for donations of bulldozers, cars, quilts and food.

In Taichang, search teams combed flattened residential buildings for trapped survivors as hundreds of unhurt residents watched from the street, where water poured from ruptured water mains.